Struct ComputedMeta 

pub struct ComputedMeta {
    pub lookback: usize,
    pub valid_rows: usize,
    pub state: Option<Vec<f64>>,
    pub origin: usize,
}

Metadata for a materialized (cached) directive column: the directive that produced it, its lookback, and how many leading rows currently hold valid values. After an append, the new rows are stale (NaN) and valid_rows lags height until fulfill recomputes the tail.

Fields

lookback: usize

The directive’s lookback (warm-up rows).

valid_rows: usize

Rows [0, valid_rows) currently hold valid values.

state: Option<Vec<f64>>

Carried recursive state for an O(new-rows) append resume: a small, fixed-size per-indicator vector capturing the internal recursive state as of the last valid row (valid_rows - 1), so an append/fulfill can continue the recursion over only the new rows, bit-identical to a fresh full recompute. None when the directive has no resume implementation (it then falls back to the correct full recompute) or the state is unknown (e.g. after a slice that did not reach the parent’s valid_rows).

origin: usize

The original-frame row that THIS (possibly sliced) frame’s row 0 maps to. 0 for a freshly-computed column; a contiguous slice from start bumps it by start. It lets an absolute-position indicator (the index family — maxindex/minindex/minmaxindex) keep emitting ABSOLUTE positions after a head-dropping slice: a sub-frame position p is original row p + origin, matching the verbatim-carried (original-absolute) head. Recursive value indicators ignore it (their state is offset-free).

Trait Implementations

impl Clone for ComputedMeta

fn clone(&self) -> ComputedMeta

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for ComputedMeta

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.